FBC, Fluid and Electrolyte Disturbances Flashcards

1
Q

Iron (ferrous sulfate, ferrous fumarate) is indicated for:

A
  • IDA rx

- prophylaxis of IDA (e.g. at risk sue to poor diet, malabsorption, mennorhagia, haemodialysis..)

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2
Q

Iron is absorbed best in its ferrous state (fe…) in the ___ and ___, its absorption is increased by ____ ___ and dietary acids e.g. ascorbic acid (vit c)
Once absorbed in blood is is bound by ____ which transports it either to be used in the ___ for ______ or to be stored as ____ in the ___, reticuloendothelial system, BM, spleen or skeletal muscle

A
  • Fe2+ in duodenum and jejunum
  • increased by stomach acid
  • bound by transferrin
  • used in bone marrow for erythropoesis or stored in liver as ferritin
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3
Q

Iron therapy can exacerbate bowel symptoms in pts with intestinal disease e.g. ___ ___ ____…
Use IV therapy in caution in pts with an ___ predisposition - due to risk of an anaphylactic reaction

A
  • e.g. IBD, diverticulitis, intestinal strictures
  • an atopic predisposition

NB: oral iron can turn pts stool black and sticky

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4
Q

Oral iron salts can reduce the absorption of other drugs including _____ and ______(so take few hours apart)

A
  • levothyroxine

- bisphosphonates

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5
Q

Vitamins

  • Thiamine (b1) is used in rx/prevention of:
  • folic acid (b9) is used in rx of _______ anaemia due to deficiency and in __ ____ to reduce risk of ___ defects
  • hydroxycobalamin (b12) is used in rx of “” anaemia and ___ ____ ____ of the cord as result of deficiency
  • Phytomenadione (vit K) is given to all newborns to prevent vit-K deficiency ___ and given to reverse the ___ effect of ___ (+/- ___ complex ___)
A
  • b1: Wernicke’s and Korsakoff’s psychosis
  • b9: Megaloblastic anaemia and 1st trimester to reduce neural tube defects risk
  • b12: Megaloblastic anaemia and subacute combined degeneration of the cord
  • vit K: prevent vit-K def. bleeding and to reverse the anticoag. effect of warfarin +/- prothrombin complex concentrate
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6
Q

In a pt with folate and B12 deficiency, what is the risk if you replace the folate first without correcting B12 deficiency?

A
  • can hasten progression of neurological manifestations of B12 deficiency
  • major risk is of provoking subacute combined degeneration of the cord
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7
Q

Pabrinex is a compound preparation of __ and __ vitamins, given by ___ as prophylaxis for patients at high risk of ____ deficiency. Dose is given 12-hrly for __ days.

A
  • Pabrinex: B and C vitamins, given by IV injections, -high risk of thiamine deficiency
  • 12-hrly for 3 days
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8
Q

To prevent NT defects, pre-conception what dose of folic acid is recommended until week 12.
If at higher risk (e.g. epilepsy), what dose is used?

A
  • 400micrograms

- 5mg

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9
Q

Give an example of colloids (plasma substitutes) and 1 indication for their administration:

A
  • gelatins, albumin
  • used to expand circulating volume in states of impaired tissue perfusion (but NaCl is usually preferred)
  • albumin is used in cirrhotic liver disease to prevent effective hypovolaemia in large-volume paracentesis (when draining ascitic fluid)
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10
Q

IV colloids e.g. gelatin, albumin contain comparatively ___, _______ active ____ in ____.
These in principle ____ readily ____ a _______ membrane and their osmotic effect ‘holds’ the infused volume in the intravascular space, (which would make them more effective at expanding circulating volume than crystalloids that do cross a membrane) why is this not usually true?

A
  • large, osmotically active molecules in suspension
  • cannot readily cross a semipermeable membrane
  • those requiring volume expansion (e.g. for sepsis) have ‘leaky’ capillaries so fluid is more rapidly lost into interstitium
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11
Q

Gelatin colloids can cause hypersensitivity and anaphylactic reactions. Colloids also contain __ so an adverse effect is when this diffuses into the interstitium, it promotes ____. Excessive plasma volume expansion can do what to the heart –> what adverse effect?

A
  • Na+
  • oedema
  • increase LV filling beyond point of maximum contractility causing fall in CO and pulmonary oedema
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12
Q

What 2 conditions should you exercise caution in prescribing colloids?

A

-heart failure
-renal impairment
to avoid volume overload

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13
Q

Colloid prescriptions:

  • for shock, Gelofusine ____mL to be given over __minutes
  • for large-vol paracentesis: ___mL albumin __% solution for every __L ascitic fluid drained
A
  • 250mL over 5 mins

- 100mL albumin 20% solution for every 2L fluid drained

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14
Q

Hartmann’s is compound sodium lactate. Given for maintenance or for resus during shock. What type of solution is it? It has one adv over 0.9% saline relating to electrolytes, what is this?

A

Crystalloid

-it has a lower chloride content so less likely to cause hyperchloremic acidosis

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15
Q

Compound sodium lactate (hartmann’s) is best avoided in severe liver disease because there may not be sufficient capacity to ?

A

-to metabolise lactate

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16
Q

With 0.9% saline you can use different concentration of K+ e.g. 5mmol/L, 20mmol/L, 40 mmol/L. How does this differ to Hartmann’s?

A

-less flexible. Hartmann’s K+ content is fixed at 5mmol/L

17
Q

Sodium Chloride (0.9% or 0.45%) are used for maintenance, for shock resus, and one extra indication? NB: glucose/sterile water could also be used for this purpose

A

-for reconstitution and dilution of drugs needed for injection/infusion

18
Q

The conc of chloride in 0.9% saline is 154mmol/L, how does this compare to the conc o chloride in the ECF and therefore what risk is associated with it’s use? Explain this

A
  • ECF is lower (100mmol/L) so risk of hyperchloraemia –> acidaemia
  • as Cl- conc rises, bicarbonate (HCO3-) conc falls to maintain electroneutrality
  • less bicarbonate -> pH rises as more K+ and H+ about
19
Q

In severe CKD what effect does impaired phosphate excretion and reduced activation of vitamin D have on calcium levels?
What gland dysfunction does this stimulate? Leading to dystrophy of what?

A
  • hypocalcaemia (and hyperphosphataemia)
  • secondary hyperparathyroidism
  • leads to dystrophy of bones aka renal osteodystrophy
20
Q

Oral calcium can cause SE in what system, e.g. ?

IV calcium gluconate for high K+ treatment has the adverse effect of what if given too fast?

A
  • oral => GIT effects e.g. dyspepsia, constipation

- IV => risk of cardiovascular collapse

21
Q

thinking about the effect vitamin D has on a certain electrolyte. In what situation would administration of vitamin D be contraindicatied?

A

Hypercalcaemia

22
Q

Oral calcium reduces the absorption of many drugs, suggest 2?

A
  • iron
  • bisphosphonates
  • tetracyclines
  • levothyroxine
23
Q

IV calcium must not be allowed to mis with sodium bicarbonate due to risk of what?

A

-risk of precipitation

24
Q

What is the dose, route and time of calcium gluconate given in sever hyperkalaemia with ECG changes:

A

-10mL of 10% IV calcium gluconate over 10 minutes

25
Q

Glucose 5% is used to provide _____ in pts unable to tolerate enough orally and for reconstitution/dilution of drugs.
Glucose 10, 20 and 50% are used to treat _____ also to treat _____

A
  • provide fluid/water

- treat hypoglycaemia and treats hyperkalaemia

26
Q

Why is dextrose given in the context of hyperkalaemia?

Clue: think about what other meds are given…

A
  • soluble insulin is given to stimulate the Na+/K+ pump to shift K+ into cells
  • glucose is given to prevent hypoglycaemia
27
Q

Why is glucose 50% rarely used and if so, delivered via a central line?

A

-its highly irritant to veins, can cause local pain, phlebitis and thrombosis

28
Q

What is the risk of giving IV dextrose (E.g. in treating hypoglycaemia) to an alcoholic?

A
  • pts at risk of thiamine deficiency, if given IV glucose can precipitate Wernicke’s encephalopathy
  • therefore, give thiamine (pabrinex) alongside
29
Q

If there is no IV access readily available and a hypoglycaemic patient requires rapid treatment, what can be given IM?

A

Glucagon (stimulates hepatic glycogenolysis and gluconeogenesis)

30
Q

Potassium chloride is used to prevent and treat potassium depletion/hypokalaemia, it should be given with which fluid, why?

A
  • with sodium chloride (saline)
  • as the infused negatively charged Cl- ions promotes retention of K+ in the serum
  • vs glucose can promote insulin release shifting K+ into cells
31
Q

In cases of hypokalaemia, what other electrolyte is commonly low and will need correction if K+ is to be normalised too.

A

-Magnesium - so always check the level and replace if needed

32
Q

In what pts is it unwarranted and dangerous to prescribe prophylactic potassium chloride for and why?

A
  • pts with renal impairment/oliguria

- they have minimal K+ losses and are v susceptible to hyperkalaemia